The NFL's Biggest Medical Concerns So Far This Offseason

Usually, the NFL injury discussion ramps up during the preseason, but this year's offseason is not exactly devoid of pivotal medical storylines either. In fact, several injuries already pose major threats to some teams' 2013 seasons.

With that in mind, let's take a look at a few of the more notable injuries, ranked in order from least to most potential impact based on a combination of injury severity, recovery progress and player importance.

Honorable Mentions

To start off, here are a few injuries that are already likely going to cost a player the entire 2013 season—and in some cases, even more.

Jahvid Best, RB (Detroit Lions)

Best's story may soon become the one at which everyone points when discussing concussion management.

After suffering multiple concussions over a relatively short time period, the former University of California standout remains unable to attain neurological clearance to return to the field. His career is likely over—a heartbreaking, yet sobering, reminder of the danger of football.

Desmond Bishop, LB (Unsigned free agent)

Bishop ruptured his hamstring—also known as a grade-three strain—during the 2012 preseason. Ruptured hamstrings are not like typical, run-of-the-mill hammies, as they require surgical re-attachment of the torn tendon to the bone as well as a prolonged recovery.

An understandably slow rehab from such a devastating injury likely played a large part in Bishop's recent release from the Green Bay Packers, and as Bleacher Report's own Zach Kruse writes, his future is unfortunately anything but certain.

Victor Butler, LB (New Orleans Saints)

Butler tore his anterior cruciate ligament (ACL) last week, an injury that almost always requires between eight months to a year from which to return. Even in the best-case scenario, he likely won't take the field this season.

Melvin Ingram, LB (San Diego Chargers)

Ingram also suffered a torn ACL, but his injury occurred in May. Nevertheless, a full recovery in time to meaningfully contribute to the 2013 season would be nothing short of miraculous.

Marcus Lattimore, RB (San Francisco 49ers)

A dislocated knee infamously sidelined Lattimore last October. He could return to the field at some point during his rookie season, but 49ers fans should be prepared to not see him in action until 2014.

10. Pierre Garcon, WR (Washington Redskins)

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It goes without saying that one of the most important assets for a wide receiver is speed—an asset that requires healthy feet. Unfortunately, Washington Redskins wide receiver Pierre Garcon's are nowhere near that.

Garcon battled a torn ligament in his foot throughout last season, and he looked like a shadow of his former self in the process, finishing the year with just 44 receptions.

The complex biomechanics of walking, sprinting and cutting place tremendous stress on the feet, often making the surgical repair of ligament injuries necessary. Garcon refused such an operation, citing the fact that doctors could not guarantee it would completely resolve the injury in his case.

As of June, the condition continues to persist. Garcon will wear specially crafted shoes for rehab, but the concern that the tear will develop into a chronic, long-term problem is a very real one.

9. Mario Manningham, WR (San Francisco 49ers)

A fairly rare injury combination, tears to the ACL and PCL result in extreme disability—often to the point that mere walking is made impossible. Additionally, the double injury significantly complicates the rehab process.

By now, Manningham is certainly well on his road to recovery. However, though all athletes are different, his eventual total recovery time will likely surpass nine months.

8. Santonio Holmes, WR (New York Jets)

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Similar to Pierre Garcon's foot injury, Lisfranc injuries carry with them the potential to drastically change the careers of wide receivers. New York Jets wideout Santonio Holmes is in danger of becoming the next victim.

Lisfranc injuries involve the disruption of the joint formed by the bones that make up the base of the toes and those that make up the heel. One possible injury mechanism is a weight falling on the midfoot, pushing it downward relative to the heel.

Unfortunately, rehabilitation is extremely tricky. It requires a significant amount of time—potentially up to a year or more—and can also produce arthritis after the fact.

Holmes suffered his injury in September 2012, but it was not until this week that the true severity of his condition came to light. According to ESPN.com's Rich Cimini, doctors classified the injury as grade four. In other words, the bases of his toes completely dislocated from his heel. In addition, he suffered a tear to one of his foot muscles.

Holmes required surgery to repair the injury—as is the case with most Lisfranc injuries in professional athletes—and is not yet near returning to the field.

7. Maurice Jones-Drew, RB (Jacksonville Jaguars)

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Keeping with the Lisfranc injury, Jacksonville Jaguars running back Maurice Jones-Drew suffered one of his own last October. However, he did not undergo surgery until December, costing him valuable rehabilitation time.

As is frequently the case—and also similar to Santonio Holmes—Jones-Drew's recovery is taking a quite a long time. The dreaded complication of foot arthritis is also a concern.

Hopefully, Jones-Drew is merely being cautious with his foot. As of now, however, nothing is certain.

6. Ed Reed, S (Houston Texans)

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First, Houston Texans safety Ed Reed planned to return from hip labrum repair surgery by the middle of training camp. Then, he didn't deny the possibility that he could miss some regular-season games. Finally, as of June 11, he suddenly won't have a "good sense" of when he could return until camp rolls around.

Just what's going on here?

Unfortunately, Reed's hip problems are probably not going away.

The hip labrum is a ring of cartilage that supports the femur—or thigh bone—as it meets the pelvis. Trauma can tear the cartilage, but surgery can also usually repair the damage.

However, if the athlete in question suffers from underlying hip arthritis—which, as I discussed with Dr. Andrew Blecher last month, Reed almost certainly does—attaining a full recovery becomes complicated. In some cases, it may even prove impossible.

Reed will almost certainly play this season. However, his increasingly unclear recovery time may represent the development of chronic hip problems for the veteran defensive back.

5. Jason Pierre-Paul, DE (New York Giants)

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The defensive line is not kind to players' spines. Just ask Jason Pierre-Paul of the New York Giants.

Pierre-Paul underwent surgery to remove a herniated intervertebral disc earlier this month. Basically, one of the cushioning cartilage discs located between his vertebrae slipped out of place and began to press on one or more of his nerves as they exited his spinal cord.

By removing part or all of the displaced disc, the pressure being placed on the nerves is lifted, and symptoms—such as pain, weakness or numbness—resolve.

That said, rehabbing from spinal surgery is no easy task. Surgical swelling must subside, and the nerves damaged by the disc must recover. The entire process can take upward of three months, and predicting an exact timetable is extremely difficult, as it depends on numerous, frequently changing factors.

All told, Pierre-Paul is in very real danger of missing regular-season time. As a defensive lineman, he is also at higher risk of suffering additional herniated discs in the future.

4. Robert Griffin III, QB (Washington Redskins)

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Robert Griffin III's blazing recovery from reconstructive knee surgery to repair his ACL and lateral collateral ligament (LCL) is well-documented. Peter King of Sports Illustrated even wrote that he believes RG3 is a lock to start Week 1 of the 2013 season.

That may happen, and at this point, it probably will not surprise anyone if it does.

However, let's take it one step at a time.

It sounds obvious, but RG3 is not ready until he is ready, and setbacks can occur at any time. For instance, during the late stages of rehab, an athlete's knee can feel normal when it is, in fact, not. Such a scenario makes it very easy to push a still-healing knee too far, resulting in re-injury.

Nevertheless, there is no reason to think or expect that will happen. That said, as long as uncompleted rehab steps remain, RG3 isn't quite there.

3. Heath Miller, TE (Pittsburgh Steelers)

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Pittsburgh Steelers tight end Heath Miller sustained a nightmarish knee injury at the end of last season: tears to his ACL, PCL and medial collateral ligament (MCL). Without three of its four main stabilizing ligaments, Miller's knee became entirely unstable.

For a better picture, take Mario Manningham's injury—one that caused extreme front-to-back knee instability due to tears to his ACL and PCL—and add inward-directed instability stemming from the ruptured MCL.

Just as Manningham's recovery is more complicated than an isolated ACL tear, Miller's is more complicated than "just" a torn ACL/PCL combo. For example, the additional MCL injury forces therapists to approach range-of-motion exercises extremely cautiously during the initial stages of rehab.

Miller should return this season, but not only is the potential of missing significant time possible, it is likely. As of last week, he remains "out indefinitely."

2. Rob Gronkowski, TE (New England Patriots)

Gronkowski's twice-fractured forearm ended up requiring four surgeries to repair the injuries and resolve resulting complications, but it is his back that may cost him some regular-season time this year.

Similar to Jason Pierre-Paul, Gronk underwent surgery on Tuesday to remove a herniated disc in his lower back. In fact, Dr. Robert Watkins performed both players' discectomies, according to Pro Football Talk's Curtis Crabtree.

As with Pierre-Paul, Gronkowski must now focus on his recovery.

Before he returns to full-contact play, Gronk will require a reasonably long amount of rehabilitation time to allow any post-surgical swelling to subside, permit his injured nerves to recover and regain any lost strength. The process could take upwards of three months, though the timetable is extremely variable from athlete to athlete.

A three-month recovery time puts Gronk out until approximately Sept. 10, and the Patriots season opener is Sept. 8. In other words, the star tight end is already in serious danger of missing significant time in 2013 well before the season even starts.

Even worse? As Northwestern University's Dr. Wellington Hsu told Ben Volin of the Boston Globe, Gronkowski's tight end position puts him at higher risk for more back problems in the future.

1. Michael Crabtree, WR (San Francisco 49ers)

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Wide receiver Michael Crabtree's ruptured Achilles tendon sent shockwaves through the San Francisco 49ers camp in late May. What's more, unlike the others on this list, Crabtree's injury represents not only a major injury that will likely cost him most of the 2013 season but also one to a key, breakout player from 2012.

In short, the 49ers receiving core looks nothing like it did last year.

Crabtree underwent surgery soon after his injury, and a projected six-month recovery time places him available around Thanksgiving.

However, that assumes nothing goes wrong. It also assumes he can return to his pre-injury level. Both assumptions are massive ones, and while everyone in the NFL community certainly feels for him, a productive, touchdown-scoring Crabtree is anything but a given for the upcoming season.

Dave Siebert is a resident physician at the University of Washington. Injury information discussed is based on his own knowledge.